Extraction of an object region (foreground region) from an image is used in many cases such as processing of photos or moving images. As an extraction technology of such an object region, for example, technology such as logic of Lazy Snapping (see Non-Patent Document 1) that extracts an object region based on a cue line in an object region drawn by the user and a cue line in a background region drawn by the user is known. Lazy Snapping is characterized in that extraction of an object region is realized only by drawing several cue lines in regions and the object region is successively re-extracted each time a line is added so that the user can add or delete a line while viewing an extraction result.